Defog loses its HM status to the returning Whirlpool.

Rock Smash, previously a TM usable on the field in the originals, is now a full-fledged HM as it has been since Generation III.

Many Gyms have been redesigned as well, some with new puzzles.

Gym Leaders, Elite Four members, Silver, and Red have animated battle sprites and battle intros, as in Platinum.

All former Berry trees have become Apricorn trees.

Apricorns can now be carried by the player in their own bag with a new item, the Apricorn Case.

Kurt and Apricorns make a return to the series along with their respective Poké Balls.Lugia and Ho-Oh each have their own unique battle music, while the legendary beasts each use differently remixed versions of their battle theme from Crystal.Like Team Galactic's Commanders followed a planetary naming scheme, the Rocket Executives are all named for various real-world rockets. Rocket Executives are also redesigned from Generation II, with four new ones appearing: Archer, Arianna, Petrel, and Proton.Team Rocket Grunts are redesigned once again.Some of these images change depending on the time of day while others change the image of the Pokémon obtainable at the location on the image at random.

An image of certain locations, like in FireRed and LeafGreen, appears when entering the location.

Unlike Kanto's remakes, which contained the same regional Pokédex as the originals, the original regional Pokédex for Johto has been slightly altered, including several Generation IV evolutions for Pokémon found in Johto.

Much like Kanto's was for its remakes, Johto's Pokédex has been redesigned.

There are a range of skins that can be used and changed at the player's will. A GB Soundskey item allows the player to switch back and forth freely between the arranged soundtrack and original chiptune soundtrack.

All the game's music is rearranged to better utilize the DS's sound capabilities.

The male player character receives a redesign and is now called Ethan, while Kris is replaced by a new female player character called Lyra.

Heartgold gba